We can use the distance formula process here....I think this might be confusing to you because there are no "numbers" involved!!! Right???
I like to do it this way.........
Subtract the "x" coordinates in any order....so (4a - 3a) = a
Now, subtract the y coordinates in any order......so (√3)a - 0 = (√3)a
Now......square both things......this gives......a2 and [(√3)a]2 = a2 and 3a2
Now, add them together = 4a2 ......Now....take the square root of this = 2a
And there you go!!!
Geometry is so weird... lol thank you so very much :) I think I am getting the concept :D